2008 Paper 8 Question 5
Comparative Architectures
(a) Why is it important to concentrate on improving the common case (e.g.
the most commonly used operations and resources) when designing a
microprocessor? [4 marks]
(b) What is the major difference between a very long instruction word (VLIW)
processor and a dynamically-scheduled superscalar processor? What impact
does this have on the complexity of the implementation in each case?
[4 marks]
(c) When designing a VLIW processor, why might variable-length instruction
bundles be preferred over fixed-length instructions? [4 marks]
(d) Some VLIW processors contain additional hardware to permit memory
reference speculation.
(i) What optimisation does memory reference speculation permit?
[4 marks]
(ii) Briefly describe the additional hardware required to support this type of
speculation. [4 marks]